ok...was battling similar situation.
there are two more items you can check.
1)In Bios, check to see if item with words
faststep or quickstep is turned on and possibly
something else that could control power saving features.
2)check Windows start up items, to make
sure there is no MFG supplied power manager
is present.

If you get it resolved one way or another,
please post back here. Interested what will
work in your case.